name & class attribute

[Ansh Kathuria]

Hey there!!

Please can anyone tell me the basic difference between the name & class attribute. In what situation both will be used?

Thanks in advance...

[Atom]

They are kind of the same. @name is a string, an @class is often an integer. They are both similar to @id for particles. Name is used quite often to "name" the pieces of a fracture, while class might be used to simply "group" a bunch of primitives that are not necessarily connected by any constraints. (i. e. for assigning materials or filtering primitives within a loop).

Edited December 29, 2021 by Atom

[Kvale]

Simplest difference is this:
The @name attribute is a string attribute. (Eg. "foo_0, foo_1")
The @class attribute is an integer attribute. (Eg. "0", "1")

Both attribute are very similar to groups. You can easily select geometry based on attributes. In the "group" tab in most nodes you can type @name="foo_1", or @class="1".
Storing groups as attributes rather than groups are actually more efficient.

The name attribute is often used in rbd simulations and other simulations that use constraints.
When packing geometry the @name attribute is used to determine how many packed pieces you'll end up with after packing.

The @class attribute is pretty much just an attribute created when calculating how many separate 3d islands there are. 

Both the connectivity node(used to create @class attribute based on primitives) and the assemble node (used to create @names) create their attributes based on how the incoming geometry is connected. 3d islands etc.

The @class attribute is often used to create names manually in vex. Eg. s@name = sprintf("foo%d", i@class");

 

Read more about @class in the documentation here.

And read more about @name in the documentation here.

[Ansh Kathuria]

Thanks Atom & Kvale for simplifying me this concept. I appreciate your answers.

Thanks!!